Modular die



March 11, 1969 w. L. LIPSCOMB MODULAR DIE Sheet File: Dec.

Fig. 2

INVEN'IUR. WILLIS L. LIPSCOMB IJY 541 & 34m

March 11, 1969 w. L. LIPSCOMB MODULAR DIE Filed Dec. 5, 1966 MO (16 .NSmm L L S L L Y U March 11, 1969 w, upsc 3,431,601

MODULAR DIE Fileci Dec. 5, 1966 1 Sheet of 5 !2 M W. 42 INVENTOR.

F WILLIS L. LIPSCOMB KImsJ-Cmw nited States Patent 3,431,601 MODULAR DIEWillis L. Lipscomb, 2208 Willow St, San Diego, Calif. 92106 Filed Dec.5, 1966, Ser. No. 599,138 US. C]. 18-44 Int. Cl. B29c 1/06 7 ClaimsABSTRACT OF THE DISCLOSURE Background of the invention The presentinvention relates to manufacturing techniques and specifically to amodular die adaptable to vacuum or pressure forming of plastics,injection molding, casting of plastics or metals, or other techniques inwhich material is formed over shaped elements.

Among the articles which are most suitable for forming with the modulardie are light control louvers or panels of cellular construction,decorative panels, screens and the like, which have an overall patternof raised or indented zones, either uniformly repetitive or somewhatrandomly arranged. Such panels are normally made on large dies made in asingle piece or in large sections of the particular pattern. Large diesare expensive to make and if a portion is damaged the entire die, or atleast a large portion of the die, must be replaced. In addition, a largeunitary die is impractical for a small number of panels due to cost.

Summary of the invention The modular die described herein is composed ofindividual shaped elements each conforming to a single feature, such asa cell, of a composite pattern. The elements are designed to interfit ina variety of arrangements on a rigid bed plate and are self-aligning inassembly. Only a few different types of elements are required to buildup a large die, with finished edges and corners and a distinctivepattern over all or parts of the die. If a portion of the die is damagedor is required to be changed, individual elements may be removed andreplaced without disturbing the remainder of the die.

Brief description of the drawings The basic die structure and varioustypes of die elements are illustrated in the drawings, in which:

FIGURE 1 is a top plan view of a portion of a die, partly assembled;

FIGURE 2 is a sectional view taken on line 22 of FIGURE 1;

FIGURE 3 is a perspective view of a base die element;

FIGURE 4 is a perspective view of a corner die element;

FIGURE 5 is a perspective view of an edge die element;

FIGURE 6 is a perspective view of an insert die element;

FIGURE 7 is a sectional view of a portion of a panel formed on the dieassembly of FIGURE 2;

FIGURE 8 is a sectional view similar to FIGURE 2, but with alternativeinsert elements at certain positions;

FIGURE 9 is a perspective view of an alternative insert element;

FIGURE 10 is a perspective view of a further alternative insert element;

FIGURE 11 is a top plan view of a hexagonal type die partiallyassembled;

FIGURE 12 is a sectional view taken on line 12-12 of FIGURE 11;

FIGURE 13 is a sectional view showing an alternative interfittingarrangement of die elements; and

FIGURE 14 is an enlarged sectional view, similar to a portion of FIGURE2, showing the configuration of the elements to ensure close fitting andeliminate gaps.

Similar characters of reference indicate similar or identical elementsand portions throughout the specification and throughout the views ofthe drawings.

Description of the preferred embodiments The die is assembled on a rigidbed plate 10 which forms the base and support for the complete die. Inthe simple configuration shown in FIGURES 1-6 the die is assembled toform a cellular panel with square cells in a uniform pattern. Fourdifferent types of die elements are all that are necessary to make upthe die and these include a base element 12, a corner element 14, andedge element 16 and an insert element 18, shown in FIGURES 3, 4, 5 and6, respectively. To facilitate accurate assembly all of the die elementshave certain common dimensions which, in this instance are thedimensions of the square cells in the pattern. In the underside of eachdie element is a threaded socket 20, preferably at the geometric centerof the common dimensioned portion for uniformity. Bed plate 10 haspro-drilled holes 22 spaced to correspond with the common dimensions ofthe die elements, that is, to align with threaded sockets 20 when thedie elements are assembled in interfitting configuration, so that eachelement is held by a single screw 24. This uniformity allows the dieelements to be assembled in a variety of different arrangements withcomplete accuracy of alignment and continuity of the pattern. However,other means of attachment may be used if necessary for special diearrangements.

Base element 12 has an upright box portion 26 of square configurationwith a depressed cavity 28 conforming to a cell of the panel to beformed, and at the lower end of the box portion is a laterally extended,symmetrically circumferential base flange 30 also of square shape. Baseflange 30 extends from each side of box portion 26 a distance equal tohalf the width of the box portion, so that when two base elements 12 aresecured with their base flanges abutting, the space between theconfronting sides of the box portions will be equal to the width of abox portion. The corners of base flange 30 have arcuate notches 34 andthe center of each side of the flange has an arcuate notch 36, toprovide clearance for screws 24 in the assembly.

Insert element 18 has a box portion 36 similar in size to box portion 26and with a corresponding cavity 38, but no flange.

Edge element 16 has a box portion 40 with a cavity 42, alsocorresponding to box portion 26, but below one half of box portion 40 isa dropped base portion 44 equal in thickness to flange 30. Base portion44- extends from one side of box portion 40 and is integral with ashoulder 46 along that side, the upper face of the shoulder beingsubstantially coplanar with the bottom of cavity 42.

Corner element 14 is somewhat similar to edge element 16, having acorresponding box portion 48' and cavity 50, but the dropped baseportion 52 and shoulder 54 extend around two adjacent sides forming theouter corner.

It should be noted that all of the box portions are of equal verticalheight, so that the upper edges are in a common plane when assembled andcorrespond to the basic plane of the panel to be formed.

In assembly, the base elements 12 are secured in place first with theirflanges 30 abutting, as in FIGURE 1, and provide a basic framework onwhich the remainder of the elements are assembled. This simplifiesalignment and layout of any particular patterns which may be used. Itwill be seen that notches 32 and 34 combine to form clearance holes forscrews in alignment with the bed plate holes 22. Corner elements 14 arethen added at the corners of the assembly, the overall size of which isdetermined by the number of base elements used. The box portions 48 reston the flanges 30 of the corner base elements when the dropped baseportions -2 are pulled down by screws 24 to seat on bed plate 10. Nextthe edge elements 16 are added and also rest on base flanges 30 alongthe outer edges of the assembly. All intervening spaces are then filledwith insert elements 18, each held by its own screw 24, to complete thecellular pattern. The relative positioning of the elements around a baseelement 12 is indicated in broken line in FIGURE 3. The shoulders 46 and54 form a continuous shoulder surrounding the assembly which, in theformed panel 56 shown in FIGURE 7, provides an edge flange 58 coplanarwith the bottoms of cells 60. If an accurate trimming guide is requireda trim bar 62 may be fitted around the periphery of the die, asindicated in broken line in FIG- URES 1 and 2. Trim bar 62 has abevelled edge 64 adjacent the shoulders 46 and 54 to form a shallowgroove, into which the panel material is forced to provide a trim flange66. This also prevents undue stretching of the panel material around theedges of the die.

The cellular cavities are by no means limited to the square form, evenwith the square configuration of the elements. In FIGURE 9, for example,an insert element 68 is shown with a hexagonal cavity 70, while FIGUREshows an insert element 72 with a cylindrical cavity 74. Either of theseis interchangeable with insert elements 18 to provide variations in thepattern. Many different shapes can be incorporated into any or all ofthe die elements to form panels of various configurations. It is notnecessary for all of the cells to be on one side of the basic plane ofthe panel. In FIGURE 8, for example, are shown insert elements 76 havingraised portions 78, which would form cells on the opposite side of thepanel from those formed in the adjacent cavities. Raised portions ofvarious configurations can be incorporated into die elements other thanthe insert elements if required.

The die elements can have a basic planform shape other than square, asin FIGURES 11 and 12, in which the pattern is hexagonal. In thisconfiguration, assembled on a bed plate 80, the die elements include abase element 82, a corner element 84, an insert element 86 and threetypes of edge elements 88, 90 and 92, which are necessary to completethe hexagonal pattern. Base element "82 has a hexagonal box portion 94with a correspondingly shaped cavity 96 and a peripheral base flange 98,also hexagonal. At the center of each edge of base flange 98 is asemicircular notch 100 to provide clearance for retaining screws 102,which hold each element in place.

Insert element 86 is a simple hexagonal box containing a cavity 104 andcorresponds to insert element 18. Edge element 88 has a half-hexagon boxportion 106 with a corresponding cavity 108 and fits over the baseflange 98 in the manner of edge element 16, an external shoulder 110providing the edge flange of a formed panel.

Edge element 90 has a box portion 112 similar to portion 106, butincludes a half-hexagon base flange 114 to fit between the base flangesof adjacent base elements 82. The outer edge of element 90 has ashoulder '116 to match shoulder 110.

Edge element 92 has a V-shaped base flange 118 to fit around a portionof base flange 98, and an upright wall 120 having a pair of V-shapedrecesses 122 to receive portions of insert elements 86. Along theoutside of wall and co-extensive therewith is a shoulder 124.

Corner element 84 is similar in many respects to edge element 92, havinga base flange 126, wall portion 128 with recesses 130 and a shoulder132, differing only in having a shoulder 134 continuing around one end.

As with the square configuration the hexagonal elements may be providedwith a variety of cavity shapes or raised portions and arranged indifferent patterns. Triangular shapes are particularly adaptable to thisconfiguration.

A simple form of the die, illustrated in FIGURE 13, uses base elements136 which are similar to the box portions of base elements 12, butomitting the base flanges. These flangeless base elements 136 aresecured directly on bed plate 10 in an alternating arrangement and thespaces are filled by insert elements 118. To facilitate assembly thebase elements 136 are shown as converging slightly toward their upperends, that is, the sides 138 are inclined inwardly and upwardly. Thesides 140 of insert elements 18 are correspondingly inclined inwardlyand downwardly. The taper need only be on the order of a few thousandthsof an inch, merely enough to facilitate insertion of the insert elementsbetween the secured base elements. Screws 24 will wedge the insertelements firmly in place between the base elements and seated on the bedplate. This simple form has one advantage over the flanged base elementassembly, in that a small die can be made, not limited to the basicthree units plus multiples of two necessary when the flanges must beaccommodated. The tapered side configuration is adaptable to all formsof the die elements.

Since the die elements can be readily produced in quantity by casting ormolding, it is desirable to minimize tolerance requirements. The mostcritical fit in the assembled die occurs at the upper edges of the boxportions, where gaps between adjacent elements would cause correspondingridges in the formed panels. To ensure close fitting without impracticalmanufacturing precision, the die elements may be made as shown in FIGURE14, which use base elements 12 and insert elements 18 as examples,although the configuration is applicable to all die elements. Insertelement 1 8 has the tapered sides 140, as shown in FIGURE 13, while thebase elements 12 have correspondingly tapered sides 142. At the upperedges of sides 140 the taper is increased so that the upper edges of boxportion 36 have widened portions 144. Similarly, at the upper edges ofsides 142 the taper is decreased to provide widened portions 146. Thewidening is on the order of one or two thousandths of an inch in eachcase, merely enough to ensure a tight fit. Since the widening occursaround the edges of cavities the die elements will normally accommodateany very slight distortion occurring by the tight fitting, withoutaffecting the formed panel. The technique of laying out an initialframework of base elements ensures uniformity throughout the die, andeliminates the possibility of progressive or accumulative misalignmentor error which could occur if the elements were merely assembled in rowsacross the die.

As illustrated the basic die is suitable for vacuum or pressure formingof sheet material, or for pressing into deformable material. By addingbarriers or walls around the die a panel could be made by pouring inliquid material which can be hardened. Further, the die can be adaptedto injection molding by securing a plate over the die at the requiredspacing, or even by using a complementary die built up in the samemanner and dimensioned to provide the necessary wall thickness in thepanel. All the techniques are well known and are mentioned to indicatethe adaptability of the modular die construction.

It is understood that minor variation from the form of the inventiondisclosed herein may be made without departure from the spirit and scopeof the invention, and

that the specification and drawings are to be considered as merelyillustrative rather than limiting.

I claim:

1. A modular die, comprising:

a rigid bed plate;

a plurality of die elements each incorporating a specific shaped portionof the die and being individually secured to said bed plate, said dieelements interfitting closely in abutting relation and forming acomposite die structure;

said die elements including (a) base elements adapted for initialsecurement to the bed plate in a predetermined overall pattern, therebyproviding a basic fixed framework for the die and preventingaccumulative error across the composite die during the assembly thereof;and

(b) insert elements secured between said base elements.

2. The structure according to claim 1 and further including edgeelements interfitting with said base and insert elements along at leastportions of the die, said edge elements having edge forming portionsabutting in continuous relation.

3. The structure according to claim 2 and further including cornerelements interfitting with said base and insert elements at corners ofthe composite die, said corner elements having edge forming portionscontinuous with the corresponding portions of said edge elements.

4. The structure according to claim 1, wherein said base elements havebase flanges extending from the lower portions thereof, the base flangesof adjacent base elements abutting and spacing the base elements apartat the correct distance to receive said insert elements in close fittinginter-relation, and said insert elements resting on said flanges.

5. The structure according to claim 4 and further including edgeelements partially overlapping said base flanges along the edges of thedie, said edge elements having dropped portions externally of and equalin thickness to said base flanges, whereby the edge elements rest on thebase flanges and said bed plate.

6. The structure according to claim 1, wherein the outer sides of saidbase elements converge upwardly from said bed plate, the outer sides ofsaid insert element being correspondingly divergent, whereby the insertelements fit in tightly wedging relation between the base elements.

7. The structure according to claim 6, wherein at least portions of theupper peripheries of said base elements and insert elements areoutwardly thickened to bind tightly against each other when assembled.

References Cited UNITED STATES PATENTS 2,443,826 6/1948 Johnson l844 X2,715,752 8/1955 Hunter l844 X 3,061,880 11/1962 Weisbach l844X3,360,829 1/1968 Germ 18-42 J. SPENCER OVERHOLSER, Primary Examiner. J.H. FLINT, JR., Assistant Examiner.

US. Cl. X.R. 249-l17,

